RFR(XS) 8036823: Stack trace sometimes shows 'locked' instead of 'waiting to lock'

[Zhengyu Gu]

This is a simple fix for incorrect lock state.

The timing on setting thread's pending monitor can result stack trace 
dump reporting incorrect lock state. The solution is to check the 
monitor's owner, if the owner is other than the current thread, then the 
monitor, is or is in process of being, set the pending monitor of 
current thread.


Bug: https://bugs.openjdk.java.net/browse/JDK-8036823
Webrev: http://cr.openjdk.java.net/~zgu/8036823/webrev.00/


Thanks,

-Zhengyu